參數(shù)資料
型號(hào)： LTC1708-PG
廠商： Linear Technology Corporation
英文描述： Dual Adjustable 5-Bit VID High Efficiency, 2-Phase Current Mode Synchronous Buck Regulator Controller
中文描述： 可調(diào)式雙5位VID高效率，2相電流模式同步降壓穩(wěn)壓控制器
文件頁(yè)數(shù)： 12/32頁(yè)
文件大?。?/td> 358K
代理商： LTC1708-PG
12
LTC1708-PG
wasted is low due to the efficient nature of the current
mode switching regulator.
THEORY AND BENEFITS OF 2-PHASE OPERATION
The LTC1708 dual high efficiency DC/DC controller, like the
LTC1628, brings the considerable benefits of 2-phase
operation to portable applications for the first time. Note-
book computers, PDAs, handheld terminals and automo-
tive electronics will all benefit from the lower input filtering
requirement, reduced electromagnetic interference (EMI)
and increased efficiency associated with 2-phase operation.
Why the need for 2-phase operation Up until the LTC1628,
constant-frequency dual switching regulators operated
both channels in phase (i.e., single-phase operation). This
means that both switches turned on at the same time,
causing current pulses of up to twice the amplitude of
those for one regulator to be drawn from the input capaci-
tor and battery. These large amplitude current pulses
increased the total RMS current flowing from the input
capacitor, requiring the use of more expensive input
capacitors and increasing both EMI and losses in the input
capacitor and battery.
With 2-phase operation, the two channels of the dual-
switching regulator are operated 180 degrees out of
phase. This effectively interleaves the current pulses
drawn by the switches, greatly reducing the overlap time
where they add together. The result s a significant reduc-
tion in total RMS input current, which in turn allows less
OPERATIOU
(Refer to Functional Diagram)
expensive input capacitors to be used, reduces shielding
requirements for EMI and improves real world operating
efficiency.
Figure 3 compares the input waveforms for a representa-
tive single-phase dual switching regulator to the new
LTC1628 2-phase dual switching regulator. An actual
measurement of the RMS input current under these con-
ditions shows that 2-phase operation dropped the input
current from 2.53A
RMS
to 1.55A
RMS
. While this is an
impressive reduction in itself, remember that the power
losses are proportional to I
RMS2
, meaning that the actual
power wasted is reduced by a factor of 2.66. The reduced
input ripple voltage also means less power is lost in the
input power path, which could include batteries, switches,
trace/connector resistances and protection circuitry. Im-
provements in both conducted and radiated EMI also
directly accrue as a result of the reduced RMS input
current and voltage.
Of course, the improvement afforded by 2-phase opera-
tion is a function of the dual switching regulator’s relative
duty cycles which, in turn, are dependent upon the input
voltage V
IN
(Duty Cycle = V
OUT
/V
IN
). Figure 4 shows how
the RMS input current varies for single-phase and 2-phase
operation for 3.3V and 5V regulators over a wide input
voltage range.
It can readily be seen that the advantages of 2-phase
operation are not just limited to a narrow operating range,
but in fact extend over a wide region. A good rule of thumb
(b)
(a)
5V SWITCH
20V/DIV
3.3V SWITCH
20V/DIV
INPUT CURRENT
5A/DIV
INPUT VOLTAGE
500mV/DIV
I
IN(MEAS)
= 1.55A
RMS
DC236 F03b
I
IN(MEAS)
= 2.53A
RMS
DC236 F03a
Figure 3. Input Waveforms Comparing Single-Phase (a) and 2-Phase (b) Operation
for Dual Switching Regulators Converting 12V to 5V and 3.3V at 3A Each. The
Reduced Input Ripple with the LTC1628 2-Phase Regulator Allows Less Expensive
Input Capacitors, Reduces Shielding Requirements for EMI and Improves Efficiency
相關(guān)PDF資料
PDF描述
LTC1708EG-PG Dual Adjustable 5-Bit VID High Efficiency, 2-Phase Current Mode Synchronous Buck Regulator Controller
LTC1709-7 RADIATION HARDENED HIGH EFFICIENCY, 5 AMP SWITCHING REGULATORS
LTC1709 RADIATION HARDENED HIGH EFFICIENCY, 5 AMP SWITCHING REGULATORS
LTC1709EG-8 RADIATION HARDENED HIGH EFFICIENCY, 5 AMP SWITCHING REGULATORS
LTC1709EG-9 RADIATION HARDENED HIGH EFFICIENCY, 5 AMP SWITCHING REGULATORS
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC1709EG 功能描述:IC REG CTRLR BUCK PWM CM 36-SSOP RoHS:否 類(lèi)別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標(biāo)準(zhǔn)包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數(shù):1 頻率 - 最大:1MHz 占空比:95% 電源電壓:2.8 V ~ 5.5 V 降壓:是 升壓:無(wú) 回掃:無(wú) 反相:無(wú) 倍增器:無(wú) 除法器:無(wú) Cuk:無(wú) 隔離:無(wú) 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤(pán) 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱(chēng):LM1771SSDX
LTC1709EG#PBF 功能描述:IC REG CTRLR BUCK PWM CM 36-SSOP RoHS:是 類(lèi)別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標(biāo)準(zhǔn)包裝:4,000 系列:- PWM 型:電壓模式 輸出數(shù):1 頻率 - 最大:1.5MHz 占空比:66.7% 電源電壓:4.75 V ~ 5.25 V 降壓:是 升壓:無(wú) 回掃:無(wú) 反相:無(wú) 倍增器:無(wú) 除法器:無(wú) Cuk:無(wú) 隔離:無(wú) 工作溫度:-40°C ~ 85°C 封裝/外殼:40-VFQFN 裸露焊盤(pán) 包裝:帶卷 (TR)
LTC1709EG#TR 功能描述:IC REG CTRLR BUCK PWM CM 36-SSOP RoHS:否 類(lèi)別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標(biāo)準(zhǔn)包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數(shù):1 頻率 - 最大:1MHz 占空比:95% 電源電壓:2.8 V ~ 5.5 V 降壓:是 升壓:無(wú) 回掃:無(wú) 反相:無(wú) 倍增器:無(wú) 除法器:無(wú) Cuk:無(wú) 隔離:無(wú) 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤(pán) 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱(chēng):LM1771SSDX
LTC1709EG#TRPBF 功能描述:IC REG CTRLR BUCK PWM CM 36-SSOP RoHS:是 類(lèi)別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標(biāo)準(zhǔn)包裝:4,000 系列:- PWM 型:電壓模式 輸出數(shù):1 頻率 - 最大:1.5MHz 占空比:66.7% 電源電壓:4.75 V ~ 5.25 V 降壓:是 升壓:無(wú) 回掃:無(wú) 反相:無(wú) 倍增器:無(wú) 除法器:無(wú) Cuk:無(wú) 隔離:無(wú) 工作溫度:-40°C ~ 85°C 封裝/外殼:40-VFQFN 裸露焊盤(pán) 包裝:帶卷 (TR)
LTC1709EG7 制造商:Linear Technology 功能描述:
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*